A national survey of middle-school students asks which subject is most challenging. Which of these samples is a representative s
ample? A. 372 sixth-graders in a certain town B. 972 seventh-graders in a certain county C. 619 eighth-graders in different states D. 400 students from various states, representing different grades, 6–8
Answer: 0.18 seconds step by step explanation: if it takes 0.09 seconds to knock down 4 dominoes, and you are trying to find out how long it will take to knock down 8 dominoes, you can see that 8/4=2, so you need to multiply 0.09 times 2 to get your answer, which is 0.18 seconds.
